The invention relates to a connection device for transmitting electric current between a stationary housing part and a rotor which can rotate with respect to the housing part, comprising a flat ribbon cable and end plug connectors which are provided in the region of the free ends of the flat ribbon cable, in particular for a steering wheel heater of a motor vehicle.
The invention also relates to a steering column/steering wheel transmission unit with a connection apparatus of this type.
DE 195 33 439 C1 has disclosed a connection apparatus for the transmission of current and/or light between two terminals. The connection apparatus comprises a first stationary housing part and a second housing part which is rotatable by a limited number of revolutions with respect thereto. A flat ribbon cable extends in windings and is arranged within the housing. The ends of the at least one flat ribbon cable are connected to the first housing part and the other ends of the flat ribbon cable to the second housing part. Such connection apparatuses are intended, for example, for transmitting current in motor vehicles between the rotatable steering wheel and a stationary housing part, in particular, a steering column switch module. The lines of the connection apparatus can be, for example, used to connect an airbag system or a control on the steering wheel side for an audio and navigation system.
If current is to be transmitted between the stationary housing part and the rotor for a steering wheel heater, lines with correspondingly large cross-sections are required due to the comparatively large quantities of current to be transmitted. Since ordinary flat ribbon cables cannot transmit such large quantities of current, one has attempted to provide two flat ribbon cables, running parallel, for transmitting the current, one for the current supply and one for the current return. The provision of several parallel flat ribbon cables for transmitting the current for a steering wheel heater is comparatively complicated and requires a relatively large number of components.
The task of this invention is therefore to propose a connection apparatus as specified above with which it is possible to transmit comparatively large quantities of current, which moreover has a comparatively compact design, and which requires only a small number of components.